update

src/_sass/gtk/apps/_xfce.scss

@@ -110,9 +110,15 @@ XfdesktopIconView.view {
  * Thunar *
  **********/
 .thunar {
-  #location-toolbar { border-bottom: 1px solid $divider; }
+  toolbar { border-bottom: 1px solid $divider; }
 
-  .standard-view.frame { border-style: none; }
+  .standard-view.frame {
+    border: none;
+
+    > .view {
+      border-radius: $corner-radius;
+    }
+  }
 
   .sidebar .view:not(:selected) { background-color: transparent; }
 

src/gtk/3.0/gtk-Compact.css

@@ -7791,7 +7791,7 @@ XfdesktopIconView.view .rubberband {
 /**********
  * Thunar *
  **********/
-.thunar #location-toolbar {
+.thunar toolbar {
   border-bottom: 1px solid rgba(0, 0, 0, 0.12);
 }
 
@@ -7799,6 +7799,10 @@ XfdesktopIconView.view .rubberband {
   border-style: none;
 }
 
+.thunar .standard-view.frame > .view {
+  border-radius: 10px;
+}
+
 .thunar .sidebar .view:not(:selected) {
   background-color: transparent;
 }

src/gtk/3.0/gtk-Dark-Compact.css

@@ -7787,7 +7787,7 @@ XfdesktopIconView.view .rubberband {
 /**********
  * Thunar *
  **********/
-.thunar #location-toolbar {
+.thunar toolbar {
   border-bottom: 1px solid rgba(255, 255, 255, 0.12);
 }
 
@@ -7795,6 +7795,10 @@ XfdesktopIconView.view .rubberband {
   border-style: none;
 }
 
+.thunar .standard-view.frame > .view {
+  border-radius: 10px;
+}
+
 .thunar .sidebar .view:not(:selected) {
   background-color: transparent;
 }

src/gtk/3.0/gtk-Dark.css

@@ -7787,7 +7787,7 @@ XfdesktopIconView.view .rubberband {
 /**********
  * Thunar *
  **********/
-.thunar #location-toolbar {
+.thunar toolbar {
   border-bottom: 1px solid rgba(255, 255, 255, 0.12);
 }
 
@@ -7795,6 +7795,10 @@ XfdesktopIconView.view .rubberband {
   border-style: none;
 }
 
+.thunar .standard-view.frame > .view {
+  border-radius: 12px;
+}
+
 .thunar .sidebar .view:not(:selected) {
   background-color: transparent;
 }

src/gtk/3.0/gtk-Light-Compact.css

@@ -7790,7 +7790,7 @@ XfdesktopIconView.view .rubberband {
 /**********
  * Thunar *
  **********/
-.thunar #location-toolbar {
+.thunar toolbar {
   border-bottom: 1px solid rgba(0, 0, 0, 0.12);
 }
 
@@ -7798,6 +7798,10 @@ XfdesktopIconView.view .rubberband {
   border-style: none;
 }
 
+.thunar .standard-view.frame > .view {
+  border-radius: 10px;
+}
+
 .thunar .sidebar .view:not(:selected) {
   background-color: transparent;
 }

src/gtk/3.0/gtk-Light.css

@@ -7790,7 +7790,7 @@ XfdesktopIconView.view .rubberband {
 /**********
  * Thunar *
  **********/
-.thunar #location-toolbar {
+.thunar toolbar {
   border-bottom: 1px solid rgba(0, 0, 0, 0.12);
 }
 
@@ -7798,6 +7798,10 @@ XfdesktopIconView.view .rubberband {
   border-style: none;
 }
 
+.thunar .standard-view.frame > .view {
+  border-radius: 12px;
+}
+
 .thunar .sidebar .view:not(:selected) {
   background-color: transparent;
 }

src/gtk/3.0/gtk.css

@@ -7791,7 +7791,7 @@ XfdesktopIconView.view .rubberband {
 /**********
  * Thunar *
  **********/
-.thunar #location-toolbar {
+.thunar toolbar {
   border-bottom: 1px solid rgba(0, 0, 0, 0.12);
 }
 
@@ -7799,6 +7799,10 @@ XfdesktopIconView.view .rubberband {
   border-style: none;
 }
 
+.thunar .standard-view.frame > .view {
+  border-radius: 12px;
+}
+
 .thunar .sidebar .view:not(:selected) {
   background-color: transparent;
 }